Many known adhesives are applied in two-part form. For example, epoxy adhesives are provided in a two-part form as a resin and an accelerator. When mixed, the accelerator facilitates the setting (or hardening or curing) of the resin.
In large scale applications, such as those for installing roofing materials and the like, the two parts, the resin and the accelerator, are carried in containers on a cart. A pump conveys the materials to an applicator gun. Known applicator guns include a frame with a barrel and handle. A manifold block, such as a steel or aluminum block is mounted at the end of the barrel.
Tubes or hoses are used as the conduit to convey material from the pumps to the manifold block. Valves are mounted to the block (typically ball valves) that are used to permit and shut-off flow of material into the manifold block. The two valves are separately actuated.
A mixing nozzle is bolted to the end of the manifold block and an applicator tube is mounted, as by threading, onto the end of the mixing nozzle. As such, mixing of the resin and accelerator occurs, in part, at the end of the manifold block and in the mixing nozzle.
There are a number of drawbacks with the present applicator system. First, the equipment is heavy and unwieldy. In particular, the manifold block is, as the name describes, a block. It is typically a block of steel or aluminum and is positioned at the end of the barrel, with the valves (also steel or aluminum) mounted to the block. Thus the majority of the weight of the gun is located at a distance from the user's hand that is holding the gun, creating a fairly substantial moment at the hand and wrist.
Moreover, in that mixing occurs at the end or exit of the manifold and in the mixing nozzle, if delivery of either or both of the components of the two-part adhesive is upset, the mixed adhesive can set up in the manifold block and/or the mixing nozzle. When this happens, it is necessary to take the applicator gun out of service, remove the mixing nozzle and clean and/or replace the manifold block and mixing nozzle. This can be a time consuming and costly situation in the cleaning and or replacement service and lost applicator operating time.
Accordingly, there is a need for an applicator gun and system that is light-weight and readily maneuvered. Desirably, such an applicator gun uses a single or double valve actuator to open and close both the resin and the accelerator valves. More desirably still, the actuator is located at or near the juncture of the gun barrel and handle, near the user's hand, to provide better ergonomics and ease of use. Still more desirably, the applicator gun includes a modular mixing nozzle and carriage to facilitate quick change-out as needed.